Right now, you need to press Enter to confirm prism shape drawing. Double-clicking a point or within the shape should confirm the drawing too, so that you don't have to move your hand from the mouse to the keyboard to perform this operation.
You can now double click to place a final point and automatically switch to dragging the prism's height. Double clicking a specific point or inside the base bounds would be a lot more work to implement.
Right now, you need to press Enter to confirm prism shape drawing. Double-clicking a point or within the shape should confirm the drawing too, so that you don't have to move your hand from the mouse to the keyboard to perform this operation.